1. Field of the Invention
The present invention pertains to a method for the identification of friend or foe (IFF) on the battlefield as well as to a system for the application of this method.
2. Description of the Prior Art
Currently used IFF systems are of the question and answer type. Their disadvantage is that they are complicated because they transmitters/receiver units on both the interrogation and the responding side and must, furthermore, have means to associate targets detected by a primary sensor with identified targets.
The present invention pertains to a battlefield IFF method which can be used to establish an immediate correlation between the detection and identification of targets, with the minimum risk of intrusion.
Another object of the present invention is a battlefield IFF system which is simpler and less expensive than prior art systems.
3. Summary of the Invention
According to the battlefield IFF method of the invention, as soon as a vehicle is detected in a zone under surveillance by an infra-red camera, at least one coded IFF interrogation is transmitted to this vehicle and, if the said vehicle is a friendly one, it transmits an infra-red laser pulse to the interrogator as soon as it receives the interrogation.
According to an advantageous aspect of a method of the invention, to prevent attempts at intrusion, the interrogator also sends no-response codes to which a friendly vehicle must not respond.
The battlefield IFF system of the invention comprises an IFF interrogator with its transmission transducer, which can move rotationally, being mechanically coupled to an infra-red receiving camera connected to a display device. Furthermore, in the said system, each friendly vehicle has a reception transducer that works in cooperation with the said transmission transducer, the said reception transducer being connected to an IFF receiver which has its IFF signals decoding output connected to a laser pulse triggering input of an infra-red laser source, the transmitter of the said source being pointed in the same direction as the said receiving transducer.